128 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57 



ORDER? 



With our present information it is not practicable to make a 

 reference of Ottoia to any of the existing orders of the Gephyrea. 

 The presence of an anterior, retractile, or introvertible proboscis, 

 and the elongate cylindrical shape of the body is essentially similar 

 to some of the Sipuncnloidea, but the direct enteric canal, and more 

 or less distinct segmentation is unknown in that order. In this 

 tentative study the ordinal classification will be omitted. 



OTTOID^, new family 



Body cylindrical, elongate ; with numerous segments that vary in 

 width posteriorly. Hooks about the mouth and also at the posterior 

 end. Proboscis papillose, introvertible, and with mouth at anterior 

 end. Enteric canal direct from mouth to anus, or possibly with 

 some slight convolutions. 



The genus Ottoia is referred to this family, and also, though 

 tentatively, Banifia. 



OTTOIA, new genus 



The description of the species O. proUfica includes aH the known 

 essential characters of the genus. 



Genotype. — Ottoia prolifica, new species. 



Stratigraphic range. — The stratigraphic range is limited to a band 

 of dark siliceous shale about 4 feet in thickness forming a part of 

 the Burgess shale member of the Stephen formation. 



Geographic distribution. — On the slope of the ridge between Wapta 

 Peak and Mount Field, north of Burgess Pass, and about 3800 feet 

 above Field on the line of the Canadian Pacific Railway, British 

 Columbia, Canada. 



Observations. — The position of Ottoia among the annelids is dis- 

 cussed under the class Gephyrea to which it is tentatively referred 

 (page 127). 



Generic name derived from Otto, name of a creek north of Presi- 

 dent Range, British Columbia, Canada. 



OTTOIA PROLIFICA, now species 



Plate 19, figs. 1-5 



Body elongate, tapering at each end when not contracted. It is 

 divided by annular lines into many segments that average seven in 

 a distance of 5 mm., except toward the posterior end where they are 

 about twice as long (fig. 5). At the anterior end there is a band of 



